using System;
namespace ch.ethz.ssh2.sftp
{
	
	/// <summary> 
	/// SFTP Open Flags.
	/// 
	/// The following table is provided to assist in mapping POSIX semantics
	/// to equivalent SFTP file open parameters:
	/// <p>
	/// TODO: This comment should be moved to the open method.
	/// <p>
	/// <ul>
	/// <li>O_RDONLY
	/// <ul><li>desired-access = READ_DATA | READ_ATTRIBUTES</li></ul>
	/// </li>
	/// </ul>
	/// <ul>
	/// <li>O_WRONLY
	/// <ul><li>desired-access = WRITE_DATA | WRITE_ATTRIBUTES</li></ul>
	/// </li>
	/// </ul>
	/// <ul>
	/// <li>O_RDWR
	/// <ul><li>desired-access = READ_DATA | READ_ATTRIBUTES | WRITE_DATA | WRITE_ATTRIBUTES</li></ul>
	/// </li>
	/// </ul>
	/// <ul>
	/// <li>O_APPEND
	/// <ul>
	/// <li>desired-access = WRITE_DATA | WRITE_ATTRIBUTES | APPEND_DATA</li>
	/// <li>flags = SSH_FXF_ACCESS_APPEND_DATA and or SSH_FXF_ACCESS_APPEND_DATA_ATOMIC</li>
	/// </ul>
	/// </li>
	/// </ul>
	/// <ul>
	/// <li>O_CREAT
	/// <ul>
	/// <li>flags = SSH_FXF_OPEN_OR_CREATE</li>
	/// </ul>
	/// </li>
	/// </ul>
	/// <ul>
	/// <li>O_TRUNC
	/// <ul>
	/// <li>flags = SSH_FXF_TRUNCATE_EXISTING</li>
	/// </ul>
	/// </li>
	/// </ul>
	/// <ul>
	/// <li>O_TRUNC|O_CREATE
	/// <ul>
	/// <li>flags = SSH_FXF_CREATE_TRUNCATE</li>
	/// </ul>
	/// </li>
	/// </ul>
	/// 
	/// </summary>
	/// <author>  Christian Plattner
	/// </author>
	/// <version>  2.50, 03/15/10
	/// </version>
	public class OpenFlags
	{
		/// <summary> Disposition is a 3 bit field that controls how the file is opened.
		/// The server MUST support these bits (possible enumaration values:
		/// SSH_FXF_CREATE_NEW, SSH_FXF_CREATE_TRUNCATE, SSH_FXF_OPEN_EXISTING,
		/// SSH_FXF_OPEN_OR_CREATE or SSH_FXF_TRUNCATE_EXISTING).
		/// </summary>
		public const int SSH_FXF_ACCESS_DISPOSITION = 0x00000007;
		
		/// <summary> A new file is created; if the file already exists, the server
		/// MUST return status SSH_FX_FILE_ALREADY_EXISTS.
		/// </summary>
		public const int SSH_FXF_CREATE_NEW = 0x00000000;
		
		/// <summary> A new file is created; if the file already exists, it is opened
		/// and truncated.
		/// </summary>
		public const int SSH_FXF_CREATE_TRUNCATE = 0x00000001;
		
		/// <summary> An existing file is opened.  If the file does not exist, the
		/// server MUST return SSH_FX_NO_SUCH_FILE. If a directory in the
		/// path does not exist, the server SHOULD return
		/// SSH_FX_NO_SUCH_PATH. It is also acceptable if the server
		/// returns SSH_FX_NO_SUCH_FILE in this case.
		/// </summary>
		public const int SSH_FXF_OPEN_EXISTING = 0x00000002;
		
		/// <summary> If the file exists, it is opened. If the file does not exist,
		/// it is created.
		/// </summary>
		public const int SSH_FXF_OPEN_OR_CREATE = 0x00000003;
		
		/// <summary> An existing file is opened and truncated. If the file does not
		/// exist, the server MUST return the same error codes as defined
		/// for SSH_FXF_OPEN_EXISTING.
		/// </summary>
		public const int SSH_FXF_TRUNCATE_EXISTING = 0x00000004;
		
		/// <summary> Data is always written at the end of the file. The offset field
		/// of the SSH_FXP_WRITE requests are ignored.
		/// <p>
		/// Data is not required to be appended atomically. This means that
		/// if multiple writers attempt to append data simultaneously, data
		/// from the first may be lost. However, data MAY be appended
		/// atomically.
		/// </summary>
		public const int SSH_FXF_ACCESS_APPEND_DATA = 0x00000008;
		
		/// <summary> Data is always written at the end of the file. The offset field
		/// of the SSH_FXP_WRITE requests are ignored.
		/// <p>
		/// Data MUST be written atomically so that there is no chance that
		/// multiple appenders can collide and result in data being lost.
		/// <p>
		/// If both append flags are specified, the server SHOULD use atomic
		/// append if it is available, but SHOULD use non-atomic appends
		/// otherwise. The server SHOULD NOT fail the request in this case.
		/// </summary>
		public const int SSH_FXF_ACCESS_APPEND_DATA_ATOMIC = 0x00000010;
		
		/// <summary> Indicates that the server should treat the file as text and
		/// convert it to the canonical newline convention in use.
		/// (See Determining Server Newline Convention in section 5.3 in the
		/// SFTP standard draft).
		/// <p>
		/// When a file is opened with this flag, the offset field in the read
		/// and write functions is ignored.
		/// <p>
		/// Servers MUST process multiple, parallel reads and writes correctly
		/// in this mode.  Naturally, it is permissible for them to do this by
		/// serializing the requests.
		/// <p>
		/// Clients SHOULD use the SSH_FXF_ACCESS_APPEND_DATA flag to append
		/// data to a text file rather then using write with a calculated offset.
		/// </summary>
		public const int SSH_FXF_ACCESS_TEXT_MODE = 0x00000020;
		
		/// <summary> The server MUST guarantee that no other handle has been opened
		/// with ACE4_READ_DATA access, and that no other handle will be
		/// opened with ACE4_READ_DATA access until the client closes the
		/// handle. (This MUST apply both to other clients and to other
		/// processes on the server.)
		/// <p>
		/// If there is a conflicting lock the server MUST return
		/// SSH_FX_LOCK_CONFLICT.  If the server cannot make the locking
		/// guarantee, it MUST return SSH_FX_OP_UNSUPPORTED.
		/// <p>
		/// Other handles MAY be opened for ACE4_WRITE_DATA or any other
		/// combination of accesses, as long as ACE4_READ_DATA is not included
		/// in the mask.
		/// </summary>
		public const int SSH_FXF_ACCESS_BLOCK_READ = 0x00000040;
		
		/// <summary> The server MUST guarantee that no other handle has been opened
		/// with ACE4_WRITE_DATA or ACE4_APPEND_DATA access, and that no other
		/// handle will be opened with ACE4_WRITE_DATA or ACE4_APPEND_DATA
		/// access until the client closes the handle. (This MUST apply both
		/// to other clients and to other processes on the server.)
		/// <p>
		/// If there is a conflicting lock the server MUST return
		/// SSH_FX_LOCK_CONFLICT. If the server cannot make the locking
		/// guarantee, it MUST return SSH_FX_OP_UNSUPPORTED.
		/// <p>
		/// Other handles MAY be opened for ACE4_READ_DATA or any other
		/// combination of accesses, as long as neither ACE4_WRITE_DATA nor
		/// ACE4_APPEND_DATA are included in the mask.
		/// </summary>
		public const int SSH_FXF_ACCESS_BLOCK_WRITE = 0x00000080;
		
		/// <summary> The server MUST guarantee that no other handle has been opened
		/// with ACE4_DELETE access, opened with the
		/// SSH_FXF_ACCESS_DELETE_ON_CLOSE flag set, and that no other handle
		/// will be opened with ACE4_DELETE access or with the
		/// SSH_FXF_ACCESS_DELETE_ON_CLOSE flag set, and that the file itself
		/// is not deleted in any other way until the client closes the handle.
		/// <p>
		/// If there is a conflicting lock the server MUST return
		/// SSH_FX_LOCK_CONFLICT.  If the server cannot make the locking
		/// guarantee, it MUST return SSH_FX_OP_UNSUPPORTED.
		/// </summary>
		public const int SSH_FXF_ACCESS_BLOCK_DELETE = 0x00000100;
		
		/// <summary> If this bit is set, the above BLOCK modes are advisory. In advisory
		/// mode, only other accesses that specify a BLOCK mode need be
		/// considered when determining whether the BLOCK can be granted,
		/// and the server need not prevent I/O operations that violate the
		/// block mode.
		/// <p>
		/// The server MAY perform mandatory locking even if the BLOCK_ADVISORY
		/// bit is set.
		/// </summary>
		public const int SSH_FXF_ACCESS_BLOCK_ADVISORY = 0x00000200;
		
		/// <summary> If the final component of the path is a symlink, then the open
		/// MUST fail, and the error SSH_FX_LINK_LOOP MUST be returned.
		/// </summary>
		public const int SSH_FXF_ACCESS_NOFOLLOW = 0x00000400;
		
		/// <summary> The file should be deleted when the last handle to it is closed.
		/// (The last handle may not be an sftp-handle.)  This MAY be emulated
		/// by a server if the OS doesn't support it by deleting the file when
		/// this handle is closed.
		/// <p>
		/// It is implementation specific whether the directory entry is
		/// removed immediately or when the handle is closed.
		/// </summary>
		public const int SSH_FXF_ACCESS_DELETE_ON_CLOSE = 0x00000800;
	}
}